U.S. patent application number 14/514559 was filed with the patent office on 2015-04-23 for sound absorber and image forming apparatus incorporating same.
This patent application is currently assigned to RICOH COMPANY, LTD.. The applicant listed for this patent is Masahiro ISHIDA, Naoki MATSUDA, Toshihiro SHIMADA. Invention is credited to Masahiro ISHIDA, Naoki MATSUDA, Toshihiro SHIMADA.
Application Number | 20150110517 14/514559 |
Document ID | / |
Family ID | 52826291 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150110517 |
Kind Code |
A1 |
ISHIDA; Masahiro ; et
al. |
April 23, 2015 |
SOUND ABSORBER AND IMAGE FORMING APPARATUS INCORPORATING SAME
Abstract
A sound absorber includes a duct member constituting a resonance
pathway, the duct member including a pathway portion communicating
ends of the duct member; a base member including a concave portion;
and a cover member including a neck in which to insert the duct
member. The cover member covers the concave portion of the base
member, and the cover member combined with the base member forms a
resonance space having a volume V The resonance pathway has
dimensions of a length LH and a cross-sectional area SH and
communicates the resonance space and an exterior of the sound
absorber. The sound absorber has a resonance frequency fH
determined by fH=(c/2.pi.)(SH/VLH).sup.1/2 and absorbs sound having
the resonance frequency fH, where c represents sound velocity.
Inventors: |
ISHIDA; Masahiro; (Kanagawa,
JP) ; SHIMADA; Toshihiro; (Tokyo, JP) ;
MATSUDA; Naoki; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ISHIDA; Masahiro
SHIMADA; Toshihiro
MATSUDA; Naoki |
Kanagawa
Tokyo
Kanagawa |
|
JP
JP
JP |
|
|
Assignee: |
RICOH COMPANY, LTD.
Tokyo
JP
|
Family ID: |
52826291 |
Appl. No.: |
14/514559 |
Filed: |
October 15, 2014 |
Current U.S.
Class: |
399/91 ;
181/284 |
Current CPC
Class: |
G03G 15/04 20130101;
G03G 21/206 20130101 |
Class at
Publication: |
399/91 ;
181/284 |
International
Class: |
G03G 21/00 20060101
G03G021/00; E04B 1/82 20060101 E04B001/82 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2013 |
JP |
2013-219861 |
Claims
1. A sound absorber, comprising: a duct member constituting a
resonance pathway, the duct member including a pathway portion
communicating ends of the duct member; a base member including a
concave portion; and a cover member including a neck in which to
insert the duct member, wherein the cover member covers the concave
portion of the base member, and the cover member combined with the
base member forms a resonance space having a volume V, wherein the
resonance pathway has dimensions of a length LH and a
cross-sectional area SH and communicates the resonance space and an
exterior of the sound absorber, and wherein the sound absorber has
a resonance frequency fH determined by fH=(c/2.pi.)(SH/VLH).sup.1/2
and absorbs sound having the resonance frequency fH, where c
represents sound velocity.
2. The sound absorber of claim 1, wherein the duct member is
configured to be replaceable with a duct member having a different
length LH and/or cross-sectional area SH.
3. The sound absorber of claim 1, wherein the base member and the
cover member form a plurality of resonance spaces.
4. The sound absorber of claim 1, wherein one of the base member
and the cover member has a recessed portion to accommodate an end
portion of the other of the base member and the cover member.
5. The sound absorber of claim 4, further comprising a sealing
member provided in the recessed portion.
6. The sound absorber of claim 1, comprising multiple types of the
duct member, each type having, based on the volume V of the
resonance space formed by the base member and the cover member,
dimensions of length LH and cross-sectional area SH that vary in
accordance with absorbed sound frequency.
7. An image forming apparatus, comprising: an image forming section
to form an image on a recording medium; and the sound absorber of
claim 1 to absorb sound generated when the image forming section
forms the image.
8. The image forming apparatus of claim 7, wherein the image
forming section includes a polygon mirror to scan a light beam
irradiating a photoreceptor, and absorbed sound frequency of the
sound absorber is a frequency of sound generated by the polygon
mirror during operation.
9. The image forming apparatus of claim 7, wherein the image
forming section includes a driving device including a motor and a
driven member driven by the motor, and absorbed sound frequency of
the sound absorber is a frequency of sound generated by the driving
device.
10. The image forming apparatus of claim 7, wherein at least one
member forming the sound absorber is configured as an exterior part
of the image forming apparatus.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application is based on and claims priority
pursuant to 35 U.S.C. .sctn.119 from Japanese Patent Application
No. 2013-219861, filed on Oct. 23, 2013 in the Japan Patent Office,
which is hereby incorporated by reference herein in its
entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] Exemplary embodiments of the present disclosure generally
relate to a sound absorber that absorbs a sound of a specific
frequency range and an image forming apparatus including the sound
absorber.
[0004] 2. Description of the Related Art
[0005] Image forming apparatuses such as copiers, plain-sheet
facsimile machines, and laser printers include a drive source such
as a motor or a drive mechanism driven by a motor. Accordingly,
noise is generated when operating the image forming apparatus.
Sources of noise include, for example, rotation of a polygon mirror
and driving of the drive mechanism.
[0006] Conventional silencing technologies are proposed, in which,
to suppress noise having a specific frequency, a technology
employing a Helmholtz resonator as a sound absorber is
provided.
[0007] However, with conventional silencing technologies employing
a Helmholtz resonator as a sound absorber, the sound frequency that
is absorbed is fixed. Thus, to change the sound frequency that is
absorbed, it is necessary to replace the sound absorber with
another sound absorber having different specifications or change
primary parts constituting the sound absorber. Accordingly, a
problem of cost increase arises.
SUMMARY
[0008] In view of the foregoing, in an aspect of this disclosure,
there is provided a novel sound absorber including a duct member
constituting a resonance pathway, the duct member including a
pathway portion communicating ends of the duct member; a base
member including a concave portion; and a cover member including a
neck in which to insert the duct member. The cover member covers
the concave portion of the base member, and the cover member
combined with the base member foams a resonance space having a
volume V. The resonance pathway has dimensions of a length LH and a
cross-sectional area SH and communicates the resonance space and an
exterior of the sound absorber. The sound absorber has a resonance
frequency fH determined by fH=(c/2.pi.)(SH/VLH).sup.1/2 and absorbs
sound having the resonance frequency fH, where c represents sound
velocity.
[0009] In an aspect of this disclosure, there is provided a novel
image forming apparatus including an image forming section and the
sound absorber. The image forming section forms an image on a
recording medium. The sound absorber absorbs sound generated when
the image forming section forms the image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The aforementioned and other aspects, features, and
advantages of the present disclosure would be better understood by
reference to the following detailed description when considered in
connection with the accompanying drawings, wherein:
[0011] FIG. 1 is a schematic view of an example of an image forming
apparatus including a sound absorber according to an embodiment of
the present invention;
[0012] FIG. 2 is a cross-sectional view of a sound absorber
according to a first embodiment of the present invention;
[0013] FIG. 3 is a cross-sectional view of a sound absorber
according to a second embodiment of the present invention;
[0014] FIG. 4 is a cross-sectional view of a sound absorber
according to a third embodiment of the present invention;
[0015] FIG. 5 is a cross-sectional view of a sound absorber
according to a fourth embodiment of the present invention;
[0016] FIG. 6 is a cross-sectional view of a sound absorber
according to a fifth embodiment of the present invention; and
[0017] FIG. 7 is a cross-sectional view of a sound absorber
according to a sixth embodiment of the present invention.
[0018] The accompanying drawings are intended to depict exemplary
embodiments of the present disclosure and should not be interpreted
to limit the scope thereof. The accompanying drawings are not to be
considered as drawn to scale unless explicitly noted.
DETAILED DESCRIPTION
[0019] Hereinafter, exemplary embodiments of the present invention
are described in detail with reference to the drawings. However,
the present invention is not limited to the exemplary embodiments
described below, but may be modified and improved within the scope
of the present disclosure.
[0020] In describing embodiments illustrated in the drawings,
specific terminology is employed for the sake of clarity. However,
the disclosure of this patent specification is not intended to be
limited to the specific terminology so selected and it is to be
understood that each specific element includes all technical
equivalents that have the same function, operate in a similar
manner, and achieve similar results.
[0021] There is provided a novel sound absorber in which a sound
frequency that is absorbed may be easily changed at low cost, and
an image forming apparatus including the sound absorber. The
following is a description of the sound absorber according to an
embodiment of the present invention and the image forming apparatus
including the sound absorber.
[0022] The sound absorber according to an embodiment of the present
invention has the following features. The sound absorber includes a
resonance space having a volume V, and a resonance pathway having
dimensions of a length LH and a cross-sectional area SH that
communicates the resonance space with the exterior of the sound
absorber. The sound absorber has a predetermined resonance
frequency fH and absorbs a sound having that predetermined
resonance frequency fH. The sound absorber is formed of a duct
member constituting the resonance pathway, a base member including
a concave portion, and a cover member including a neck in which to
insert the duct member. The cover member covers the concave portion
of the base member, and the cover member combined with the base
member forms the resonance space.
[0023] The duct member may be replaced with a duct member having at
least one of length LH and cross-sectional area SH changed to a
desired size.
[0024] An example of the image forming apparatus including the
sound absorber according to an embodiment of the present invention
is as follows.
[0025] FIG. 1 is a schematic view of an example of an image forming
apparatus 20 including the sound absorber according to an
embodiment of the present invention. In the present embodiment, the
image forming apparatus 20 is a copier. The image forming apparatus
20 is generally called a console-type copier and has a high overall
height so the image forming apparatus 20 may be used set on the
floor. The image forming apparatus 20 is formed of an upper part 1
and a lower part 2. The upper part 1 is an image forming section
including an optical unit 4 having optical elements inside a case
3, and units for image formation provided below the optical unit 4.
The optical elements may include a rotationally driven polygon
mirror to scan a light beam that irradiates a photoreceptor. The
lower part 2 includes multiple trays 5. An automatic document
feeder 6 (hereinafter referred to as ADF 6) is mounted on top of
the upper part 1.
[0026] When a document is placed on a document table 7 provided at
an upper portion of the ADF 6, the document is automatically
conveyed to and stops on a exposure glass 8 supported by the case 3
of the optical unit 4. Next, a light source 9 of the optical unit 4
at a position shown in FIG. 1 moves in a direction to the right. A
surface of the document facing the exposure glass 8 is illuminated
by the light source 9, and an electrostatic latent image of the
illuminated surface of the document is formed on a photoreceptor fH
via an image forming optical system 10 inside the optical unit
4.
[0027] It is to be noted that the photoreceptor 11 rotates in a
clockwise direction as shown by arrow D in FIG. 1 and the surface
of the photoreceptor 11 is uniformly charged by a charger 12 when
rotating. The electrostatic latent image is formed on the uniformly
charged surface of the photoreceptor 11 with the above-described
image forming optical system 10.
[0028] Then, the electrostatic latent image on the photoreceptor 11
is rendered visible as a toner image with toner supplied from a
developing unit 13.
[0029] At the lower part 2, a transfer sheet 14 serving as a
recording medium is conveyed to the photoreceptor 11 from one of
the trays 5 provided in the lower part 2. The toner image on the
photoreceptor 11 is transferred to the transfer sheet 14 with a
transfer charger 15. The toner image is fixed to the transfer sheet
14 when the transfer sheet 14 having the toner image passes through
a fixing unit 16. Then, the transfer sheet 14 is ejected from the
image forming apparatus as a completed copy. It is to be noted that
the image forming apparatus 20 shown in FIG. 1 has a configuration
in which duplex copying may be conducted, however, description with
respect to such is omitted herein for brevity.
[0030] After transfer of the toner image to the transfer sheet 14,
residual toner on the photoreceptor 11 is removed by a cleaning
unit 17.
[0031] As described above, the image forming apparatus 20 shown in
FIG. 1 includes various parts and units, and driven members are
driven by a driving force of one or more motors. Further, the
above-described various parts and units are supported by a
structural skeleton.
[0032] A Helmholtz resonator as a sound absorber according to an
embodiment of the present invention is provided in the image
forming apparatus 20. The following is a description of embodiments
of the sound absorber according to an embodiment of the present
invention.
Embodiment 1
[0033] FIG. 2 is a cross-sectional view of a sound absorber 30 of a
first embodiment of the present invention. The sound absorber 30
forming a Helmholtz resonator includes a resonance space 36 having
a volume V, and a resonance pathway 37 having dimensions of a
length LH and a cross-sectional area SH that communicates the
resonance space 36 with the exterior of the sound absorber 30.
[0034] The Helmholtz resonator has a resonance frequency fH
determined by the following formula 1:
fH=(c/2.pi.)(SH/VLH).sup.1/2 (1)
[0035] Accordingly, the Helmholtz resonator operating as the sound
absorber 30 absorbs a sound having the resonance frequency fH. In
formula 1, "c" represents sound velocity. At the resonance
frequency fH, the Helmholtz resonator traps acoustic energy going
to the resonance space 36 and a silenced state is obtained outside
of the Helmholtz resonator (i.e., inside of an image forming
apparatus). More specifically, sound having the resonance frequency
fH is trapped by the Helmholtz resonator. Accordingly, the
resonance frequency fH does not escape out of the image forming
apparatus and a silencing effect is obtained.
[0036] The sound absorber 30 is formed of three members, a duct
member 31, a cover member 32, and a base member 33. The duct member
31, the cover member 32, and the base member 33 are molded members
made of a synthetic resin and are easily manufactured at low
cost.
[0037] The duct member 31 includes a circular disk-shaped flange
portion 3 lb, a cylinder-shaped tube portion 31c, and a pathway
portion 31a operating as the resonance pathway 37 that communicates
ends of the duct member 31.
[0038] The cover member 32 includes a flat plate-shaped lid portion
32a, and a cylindrical neck 32b formed in the flat plate-shaped lid
portion 32a. The duct member 31 is inserted in the cylindrical neck
32b. More specifically, when the duct member 31 is inserted in the
cylindrical neck 32b of the cover member 32, the circular
disk-shaped flange portion 31b of the duct member 31 contacts a rim
of the cylindrical neck 32b of the cover member 32, and the duct
member 31 is mounted in place.
[0039] The base member 33 includes a concave portion 33a defining
the resonance space 36. More specifically, the resonance space 36
is formed by combining the base member 33 with the cover member 32
in a manner in which an opening portion 33b of the concave portion
33a of the base member 33 is covered with the flat plate-shaped lid
portion 32a of the cover member 32. It is to be noted that as long
as the resonance space 36 has the predetermined volume V. shape of
the resonance space 36 formed by the base member 33 and the cover
member 32 may be changed according to need. For example, the shape
of the resonance space 36 may be a cuboid, a cube, a sphere, or any
arbitrary shape that may be set between various image forming
devices provided in an image forming apparatus.
[0040] In the sound absorber 30, a specific frequency range is
selected as the resonance frequency fH. More specifically, the
specific frequency range selected as the resonance frequency fH may
be a frequency of a sound generated by a polygon mirror, or may be
a frequency of a sound generated by a driving device, such as a
conveyance mechanism 22 in the image forming section of the image
forming apparatus 20, including a motor and a driven member, such
as a conveyance drive roller 21, driven by the motor.
[0041] In the sound absorber 30 of the first embodiment, multiple
types of the duct member 31 may be prepared, based on the volume V
of the resonance space 36 formed by the base member 33 and the
cover member 32, depending on the sound frequencies that may be
absorbed. Thus, more specifically, multiple types of the pathway
portion 31 a of the duct member 31 are prepared having, based on
the volume V of the resonance space 36 formed by the base member 33
and the cover member 32, dimensions of the length LH and the
cross-sectional area SH in accordance with the sound frequencies
that are to be absorbed.
[0042] Each of the above-described multiple types of the duct
member 31 has a cylindrical shape with a fixed outer diameter, with
at least one of the length LH and the cross-sectional area SH of
the pathway portion 31a changed. Accordingly, all of the
above-described multiple types of the duct member 31 may be
inserted into the cylindrical neck 32b of the cover member 32.
[0043] According to the first embodiment, a desired sound frequency
absorption is obtained with respect to image forming apparatuses
having a common housing but generating noise of different
frequencies by selecting and setting the appropriate duct member
31. Due to not needing to change a large part of the sound absorber
30, absorbed sound frequency may be changed at low cost.
[0044] In addition, even in a case in which a sound frequency
generated by an image forming apparatus changes after continued
use, the changed sound frequency may be cancelled out by changing
the duct member 31 to change absorbed sound frequency. Further,
absorbed sound frequency may be set according to individual user at
low cost. It is to be noted that the shape of the duct member 31 is
not limited to a round cylindrical shape and may have other shapes
such as a square cylinder.
Embodiment 2
[0045] The following is a description of a sound absorber 40 of a
second embodiment of the present invention.
[0046] FIG. 3 is a cross-sectional view of the sound absorber 40 of
the second embodiment of the present invention. The sound absorber
40 of the second embodiment includes a base member 43 and a cover
member 42 that forms multiple resonance spaces. As shown in FIG. 3,
three resonance spaces 46-1, 46-2, and 46-3 are formed. The cover
member 42 of the sound absorber 40 includes three necks 42a-1,
42a-2, and 42a-3. Duct members 41-1, 41-2, and 42-3 are inserted in
the three necks 42a-1, 42a-2, and 42a-3, respectively.
[0047] In the sound absorber 40 of the second embodiment,
appropriate values with respect to volumes V1, V2, and V3 are set
for the resonance spaces 46-1, 46-2, and 46-3, respectively.
Further, appropriate values with respect to dimensions of a length
LH1 and a cross-sectional area SH1, dimensions of a length LH2 and
a cross-sectional area SH2, and dimensions of a length LH3 and a
cross-sectional area SH3 are set for the duct members 41-1, 41-2,
and 41-3, respectively. Accordingly, absorption of three different
sound frequency ranges is obtained.
[0048] It is to be noted that the sound absorber 40 of the second
embodiment takes up a large area. Thus, the base member 43 may be
configured as an exterior part of an image forming apparatus,
thereby reducing the number of exterior parts of the image forming
apparatus.
Embodiment 3
[0049] The following is a description of a sound absorber 50 of a
third embodiment of the present invention.
[0050] FIG. 4 is a cross-sectional view of the sound absorber 50 of
the third embodiment of the present invention. The sound absorber
50 of the third embodiment has a configuration that is basically
the same as the sound absorber 30 of the first embodiment. More
specifically, the sound absorber 50 is formed of a duct member 51,
a cover member 52, and a base member 53. In the sound absorber 50,
however, a groove-shaped recessed portion 54 is formed in the cover
member 52 to accommodate an end portion of the base member 53. In
the sound absorber 50 of the third embodiment, the cover member 52
and the base member 53 are reliably mounted in place, and air
leakage between the cover member 52 and the base member 53 is
securely prevented. Thus, sound absorbing performance is
enhanced.
Embodiment 4
[0051] The following is a description of a sound absorber 60 of a
fourth embodiment of the present invention.
[0052] FIG. 5 is a cross-sectional view of the sound absorber 60 of
the fourth embodiment of the present invention. The sound absorber
60 of the fourth embodiment has a configuration that is basically
the same as the sound absorber 50 of the third embodiment. More
specifically, the sound absorber 60 is formed of a duct member 61,
a cover member 62, and a base member 63. In the sound absorber 60,
however, a groove-shaped recessed portion 64 is formed in the cover
member 62 to accommodate an end portion of the base member 63, and
a sealing member 65 is provided in the groove-shaped recessed
portion 64, enhancing the seal between the cover member 62 and the
base member 63.
[0053] With the sound absorber 60 of the fourth embodiment, air
leakage between the cover member 62 and the base member 63 is
reliably prevented and sound absorbing performance is enhanced.
Embodiment 5
[0054] The following is a description of a sound absorber 70 of a
fifth embodiment of the present invention.
[0055] FIG. 6 is a cross-sectional view of the sound absorber 70 of
the fifth embodiment of the present invention. The sound absorber
70 is formed of a duct member 71, a cover member 72, and a base
member 73. In the sound absorber 70, a groove-shaped recessed
portion 74 is formed in the base member 73 to accommodate an end
portion of the cover member 72.
Embodiment 6
[0056] The following is a description of a sound absorber 80 of a
sixth embodiment of the present invention.
[0057] FIG. 7 is a cross-sectional view of the sound absorber 80 of
the sixth embodiment of the present invention. The sound absorber
80 of the sixth embodiment has a configuration that is basically
the same as the sound absorber 70 of the fifth embodiment. In the
sound absorber 80 of the sixth embodiment, however, a sealing
member 85 that enhances air-sealing is provided in a groove-shaped
recessed portion 84.
[0058] In view of the foregoing, in the sound absorber of the
present invention formed as the Helmholtz resonator, the duct
member forming a duct part of the Helmholtz resonator may be
selected and set to obtain appropriate sound frequency absorption
with respect to image forming apparatuses having a common housing
but generating noise of different frequencies. Further, absorbed
sound frequency may be changed without changing a large part of the
sound absorber.
* * * * *